The present invention relates generally to closures for fluid sample cups, preferably blood sample cups, and methods of making the same.
Prior to the present invention, errors in blood analyzing occurred as a result of evaporation of water from the blood sample and as a result of contamination of the blood sample which occurred while the sample was located in the sample cup awaiting analysis. Thus, a need has arisen for a closure which prevents evaporation and contamination of the blood sample.
Past attempts to combat this problem of evaporation and contamination, while reducing this problem, have been ineffective in overcoming it. Further, some of the attempts have prevented the automatic operation of blood analyzers in that the pipette could not pierce the closures and thus prior closures had to be removed from the sample cups before analysis. Specifically, prior closures which were individually applied to sample cups in a rotary tray of the analyzer had to be hand removed before operation of the analyzer which is very awkward and slow while closures which covered all the sample cups in the rotary tray were easily removable but were not effective in preventing evaporation and contamination. Thus, a need has arisen for a closure which may remain on the sample cup and allow the automatic operation of the blood analyzer.
Further, errors in blood analyzing occurred because residue of blood serum remained on the pipette of the blood analyzer and thus was transferred to the next sample cup. Thus, a need has arisen for preventing such blood residue transference between samples.